Balloon catheters, having expandable balloon members located at the distal end of the balloon catheter, are employed in a variety of medical procedures. These procedures include using balloons as dilatation devices for compressing atherosclerotic plaque which results in a narrowing of the arterial lumen. They also include using balloons for delivery and expansion of prosthetic devices such as stents, to a lesion site, i.e. vessel obstruction, within a body vessel.
One medical procedure where balloon catheters are employed is percutaneous transluminal coronary angioplasty, or balloon angioplasty, which is a non-invasive, non-surgical means of treating peripheral and coronary arteries. This technique consists of inserting an uninflated balloon catheter into the affected artery. Dilation of the diseased segment of artery is accomplished by inflating the balloon which pushes the atherosclerotic lesion outward, thereby enlarging the arterial diameter.
In the most widely used form of angioplasty, a balloon catheter is guided through the vascular system until the balloon, which is carried at the distal end of a catheter shaft is positioned across the stenosis or lesion, i.e., vessel obstruction. An expandable stent can be included on the balloon. The balloon is then inflated to apply pressure to the obstruction whereby the vessel is opened for improved flow. Expansion of the balloon causes expansion of the stent to provide support to the vessel wall.
Within the vasculature however it is not uncommon for stenoses to form at a vessel bifurcation. A bifurcation is an area of the vasculature or other portion of the body where a first (or parent) vessel is bifurcated (branches) into two or more branch vessels. Where a stenotic lesion or lesions form at such a bifurcation, the lesion(s) can affect only one of the vessels (i.e., either of the branch vessels or the parent vessel) two of the vessels, or all three vessels. Many prior art stents however are not wholly satisfactory for use where the site of desired application of the stent is juxtaposed or extends across a bifurcation in an artery or vein such, for example, as the bifurcation in the mammalian aortic artery into the common iliac arteries.
Desirable characteristics for such assemblies include flexibility and maneuverability for ease of advancement through the body vessel, as well as thin walls and high strength. Furthermore, it is desirable to control dimensional changes in medical balloons including both radial and longitudinal expansion characteristics.
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Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.